The research aim of the Work Group is to study neural activity patterns of many neurons in multiple brain regions which mediate computation specific to behavioral context. Critical preliminary experiments in cerebral cortex, hippocampus and caudate in awake behaving rats have shown the feasibility of studies of the neural basis of cognitive behavior, and of solving technical problems related to obtaining recordings from multiple isolated single neurons in awake behaving rats. Dr. Woodward at Dallas will direct studies of simultaneous activity of many neurons in basal ganglia in behavioral tasks involving sensorimotor integration linked to significance of auditory cues. Dr. Chapin in Philadelphia will study regulation of gating of sensory input to SI cortex within behavioral context. Dr. Deadwyler at Winston-Salem will study neural circuit responses related to spatial and temporal aspects of learning and memory in the hippocampus of behaving animals. Dr. Hoffer at Denver will study monoamine levels in behaving rats with high speed in vivo chronoamperometry. Dr. BeMent at Michigan will develop new semiconductor microprobes and apply them for simultaneous recording and stimulation in rat motor cortex. Core activity will involve the incorporation of existing software and hardware designs for the participating laboratories into an advanced computer system with signal processing electronics for studies in behavioral neurophysiology. A facility will be established to develop strategies for statistical analysis of brain neural ensembles. A facility for specifying computational models of cerebral cortex, neostriatum and hippocampus will be used to examine emergent computational properties of intrinsic neural networks.The directors for each research component will disseminate the capabilities of the resource for other researchers at the local institutions. The Work Group Director, an Executive Committee, and an External Advisory Committee will work together in developing the Program.